The company is called TSA, they are contracted through Telstra to sell products,

I was offered a 30% discount on my bill to which I agreed, they had all my personal information as they have access to it being a third party to Telstra.

Signed me up to 3 new phone plans with different mailing addresses without my consent.

Account is on hold while Telstra investigates, they have all the voice recording and the employee ID’s.

I don’t know how they benefit in this situation.

Scammers

Scam caller, asks for your Telstra One Time Pin to gain access to Account, then obtains Credit Card information. Reported to Telstra and they were able to share with me the interaction the scammer had pretending to me before he suddenly ending interaction (assuming when I wouldn't provide them the PIN)

Caller: Scamer

They are trying to gain access to your phone account.
They contact Telstra online with your information requesting to change the address. Telstra then sends your phone a one time pin number valid for 20 mins. The scamer then rings within the 20 mins posing as a Telstra employee. They'll tell you they can give you a 30% discount on something and to check your messages for a one time pin code. Don't give it to them. They'll gain access to your account, change your address and order a new phone.
Delivery to their newly created address 👍🏻

Caller: Indian male

Couldn’t understand what he was saying though a very thick accent. Something about 30% off. Call was immediately preceded by 2 “one time pin” requests from Telstra which was strange as I was no where near my phone when they came though.

Caller: Indian male

Couldn’t understand what he was saying through a very thick accent, something about 30% off. Phone call was immediately preceded by 2 strange “one time pin” requests from Telstra

Apparently Telstra

Couldn't understand the caller

maybe optus . don't know why, don't deal with them.
Asked for me by christian name, but didn't leave a message.
Asian lady obviously at a call centre.